The Reason

An unusual ladies form watch with a day and night, 24 hour rotating disc encompassing the balance and escapement with the opposite side housing an engraved titanium moon. The watch includes hand engraving back and front, guilloché, unusual diamond setting on the inside as well as outside of the bezel. Mother of pearl and lapis lazulite.

(Launched in 2013)

Functions: offset minutes & hours with a 24 hour, day & night indication at 12 o’clock set with the balance and escapement.

Winding automatic Power reserve 57 hours Calibre 78CS Jewels 45 Balance-spring Silicon Frequency 3.5Hz Case metal white gold Back and front Sapphire Height 40,05mm Width 32mm Thickness 10,6mm Water-resistant 30m

Each Breguet ‘Reine de Naples’ watch has a unique serial number associated to the particular model which is found both on the dial and case back, then recorded in the company archives.

The profile of the case continues the overall design aesthetics of the egg form but flattened for ergonomics.

The bezel inner and outer surfaces are set with 143 diamonds weighing approx. 1.45 cts.

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The case back has been removed showing the complete calibre which follows the same shape as the case.

The rotor weight removed showing an unobstructed view of the calibre bridges.

The rotor weight removed, held in place on to its arbour by a conical shaped screw. The face and rays/arrows are hand engraved.

The movement is held into the case by two large screws and clamps set at 3 & 9 o’clock.

The movement and dial assembly removed from the case.

The dial removed from the movement. The finish is a combination of 3 styles of guilloché and circular graining on a gold base which is silvered after it is completed and a final protective layer added to avoid tarnishing over time. The Breguet secret signatures are found between 4 & 5 and 7 & 8.

The dial removed showing the hidden mechanics.

Recto-verso of the dial.

Breguet hands, minute and hour. Made in hardened and tempered steel, polished then thermically blued. The eyes of the hands are filled with SuperLuminova to give contrast between the hands and the blue lapis disc as they cross it.

The bridge side of the movement, (removed from the case).

The dismantled white gold case. Water resistant to 30m. The seal for the bezel is machined into the centre of the case, for the case back the seal is placed into a machined gully in the case back.

The case back is held in place by 6 gold casing screws.

The bezel is held in place by 6 screws that are placed from the inside of the case and hidden by the case back when it is in place.

An exploded view of the automatic mechanism.

The automatic mechanism removed.

The automatic assembled block removed from the movement. The large diameter of the rotor axe pivots inside a ceramic bearing.

The train bridge removed showing the train wheels leading from the barrel to the pinion which drives the day-night disc.

The cloud like decoration on the higher level of the bridge is executed by hand.

The train bridge with a combination of hand and machine engraved words and numbers.

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The barrel bridge and train removed showing the barrel and final wheels of the going train.

The barrel bridge. When the bridges are decorated/engraved and circular grained they are placed onto a working main-plate to assure design continuity between components.

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The movement sitting in its holder.

The day and night discs steel bridge removed from the movement. It also acts as the superior section of the dial with the minutes and hours machined into it and then laquered by hand for contrast and continuity with the dial.

The bridge removed.

A partially exploded view of the disc assembly.

The balance and escapement are set into the 24 hour turning disc. The blue is lapis lazuli, the moon made from titanium, clouds made from mother of pearl and stars from white gold.

The disc removed showing the ceramic bearing.

The underside of the disc, the support/wheel is made from titanium.

An exploded of the disc.

The titanium support/wheel.

The balance wheel with silicon balance spring. The balance wheel is specifically made for this calibre with an extended wheel rim which is diamond cut to generate a form which catches the light as it oscillates. The balance is free-sprung and adjusted/regulated by the 4 timing screws.

Recto-verso of the main-plate.


The Breguet Reine de Naples day and night includes a technically and artisanally complex execution. Driving a massive comparative to proportions stone set disc including escapement and balance in a relatively small calibre. The watch has a combination of materials and techniques highly diverse but well integrated, from guilloché, engraving to stone setting plus lapidary. The calibre is assembled and adjusted by hand with certain elements held in place by screws holding bridges from both sides due to the limited space and complex forms.

The strap is held onto the case through two bars at 12 and 6. Each bar comprises of two pieces which screw together. The below tool shows how the strap is changed, the case sits in a form marrying its shape and the two screw drivers aligned with the two piece screwed bar.

Some of the supports for the movement and disc.


To learn more about Breguet